From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 67EDB242D84 for ; Wed, 2 Jul 2025 21:49:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751492990; cv=none; b=NZtVQFI+xaWJNCt8sjTW748waYQ2jrELMTUnQfww5xLAfmTsHHLlzHgXOODY21+QUSzGad0xZHH5Sde3f62HeKh22Y1UOXm6VtykDIPilblVeSpCtFJl+9Kj+mwen/hl/6TFiBmAfkkfkTDQ8EI13wwSirfNnJH6nvGpDoEYc9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751492990; c=relaxed/simple; bh=OCa2o+c8VjyxJ2s+GyfQFsyRKEx209cXGEDt7nnFU+A=; h=Content-Type:MIME-Version:Subject:From:Message-Id:Date:References: In-Reply-To:To:Cc; b=utdugmdX25kPYoONK+D5/9ymDtxZDY2HAZ4XqUlg1LHBJ8AgIT9ATxm2tTkCDdaEhWcm6EJQV2AawfthsF7zk4k3p3ZWBFUMLHYH9AryCj1cmqfQvijA9dX3wHTAPbrylF8OiiVgwPV+srOEgqZFtR69jn2jBb0BYyiOueijdUg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SzUkN8LU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SzUkN8LU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB570C4CEEE; Wed, 2 Jul 2025 21:49:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751492990; bh=OCa2o+c8VjyxJ2s+GyfQFsyRKEx209cXGEDt7nnFU+A=; h=Subject:From:Date:References:In-Reply-To:To:Cc:From; b=SzUkN8LUloYEzeWqfS22/JAcJFmoqtCKLHgKdweBWIjD9kTUhgcHK+eVbQlygi+9Q yJYXpf46H7Sv/2uW1bugZ9I/PUsIF2RMY9aMcrz7dsxzGBnZJFJDIcnRuvVY6A6INk Em0ZrxnK8kJI+6LZ37Gkv5SVlIEe4mnV8d5Z+G3NOE4QJvI4QE07/pQv3V361LHmb1 DeLztSWwscwMRYgUswAl5oRAHP3bZN1vRcCJpGiSuFaGoQRGEdMQbvA6XlfUmFgIT5 Se+z8ADaqLyUYBTeV2i3aQ6W77RjxoSx4pbOEu5nZHK6T7WLdcfeuwVq9wBwGxejoG X1an6BuGsmz0g== Received: from [10.30.226.235] (localhost [IPv6:::1]) by aws-us-west-2-korg-oddjob-rhel9-1.codeaurora.org (Postfix) with ESMTP id ADDF1383B273; Wed, 2 Jul 2025 21:50:15 +0000 (UTC) Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH] net/sched: Always pass notifications when child class becomes empty From: patchwork-bot+netdevbpf@kernel.org Message-Id: <175149301450.875317.4500699769123962307.git-patchwork-notify@kernel.org> Date: Wed, 02 Jul 2025 21:50:14 +0000 References: In-Reply-To: To: Lion Ackermann Cc: netdev@vger.kernel.org, jiri@resnulli.us, xiyou.wangcong@gmail.com, jhs@mojatatu.com, victor@mojatatu.com, mincho@theori.io Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski : On Mon, 30 Jun 2025 15:27:30 +0200 you wrote: > Certain classful qdiscs may invoke their classes' dequeue handler on an > enqueue operation. This may unexpectedly empty the child qdisc and thus > make an in-flight class passive via qlen_notify(). Most qdiscs do not > expect such behaviour at this point in time and may re-activate the > class eventually anyways which will lead to a use-after-free. > > The referenced fix commit attempted to fix this behavior for the HFSC > case by moving the backlog accounting around, though this turned out to > be incomplete since the parent's parent may run into the issue too. > The following reproducer demonstrates this use-after-free: > > [...] Here is the summary with links: - net/sched: Always pass notifications when child class becomes empty https://git.kernel.org/netdev/net/c/103406b38c60 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html